In recent weeks, there's been discussion about the best fabrics to use when making face masks. Ours are made of 100% cotton, which is on the list. Read on to learn about some of the other options.
*Disclaimer: The article is based solely on opinion. None of the statements below are based on tests, experience, or scientific study of face masks. The goal of this article is to provide information on cloth face masks and fabric suggestions to the best of our knowledge. It should not to be perceived as professional advice. No tests were performed to substantiate the recommendations. There is no guarantee that following them will prevent infection. The company holds no responsibility or liability about performance of the fabrics or masks made using them.
Searching for guidance on protective masks, we found this information on face masks being regulated by the FDA as medical devices. It states, “While a face mask may be effective in blocking splashes and large-particle droplets, a face mask, by design, does not filter or block very small particles in the air that may be transmitted by coughs, sneezes or certain medical procedures. Face masks also do not provide complete protection from germs and other contaminants because of the loose fit between the surface of the face mask and your face.”
The FDA Guidance for Industry and FDA Staff on Surgical Masks is a complete guide on how to prepare a Pre-market Notification submission for selling surgical masks and other protective masks. The bulk of the submissions are for single use masks made using layers of polypropylene, held in place using ear loops or elastics or tie strings, to be disposed after each use.
The CDC’s guidance on respirators for non-occupational use says, “Three key factors are required for a respirator to be effective: (1) the respirator has to be put on correctly and worn during the exposure; (2) the respirator must fit the user’s face snugly to minimize the number of particles that bypass the filter and get into the breathing zone through gaps between the user’s skin and the respirator seal; and (3) the respirator filter needs to be highly effective at capturing particles that pass through the filter."
Designing effective face masks for good protection from infection is not an easy task. These devices are regulated by the FDA and there are rigorous testing requirements to make sure they are safe and effective. When designing one some important things to keep in mind seem to be*:
Adequate Size & Good Fit to cover the nose and mouth to allow for entry of air only through the mask. Knit fabrics have some stretch and can be used to make masks that fit the face snugly without being uncomfortable, many woven fabrics have no stretch (like the single use polypropylene ones see paragraph 1). A good, snug fit depends on the construction, to make sure there are no gaps at the edges that can allow entry/escape of particles. Patterns for face masks are available on the internet, but all may not be effective.
Adequate Filtration to prevent transfer of particles while breathing, this can be accomplished by using multiple layers of closely knitted (or woven) fabrics. (This is not based on any testing, just based on the fact that surgical masks use three layers of polypropylene, and the N95 respirator construction that has 4 layers – outer hydrophobic, middle non-woven for filtration, a support layer and an inner stay dry.)
Breathability to allow for easy respiration. Layering breathable fabrics allows for good breathability along with good filtration. Surgical masks generally use three layers of thin polypropylene, while respirators have 4 layers of which one is a support layer.
Protection from microbes might be possible by using antimicrobial fabrics that have a wide spectrum of activity, such as those treated with the Antimicrobial Silvadur. There are advocates for and against antimicrobial fabrics, this is a choice you have to make. Based on recent reports it is advisable to stay away from nanosilver treatments until they have been vetted for being safe.
- Comfort against the skin is important especially with the high humidity condition created by breathing through the mask and the risk of saturation. Using a stay dry, wicking fabric on the inside can move the moisture away from the face would make the mask comfortable to wear.
Holding the mask in place can be accomplished by using elastic ear loops or elastic bands that go around the head which seems to be a more secure method.
A good washing/sanitizing routine is important for reusing them.